WSE staff have been providing floodplain management consulting services to clients for over 30 years. From assessing current flood hazards to evaluating potential flood mitigation alternatives, WSE has worked extensively in floodplains across the Pacific Northwest.

For over 25 years, Jeff worked as a consultant to the Pacific Northwest Region (Region X) of the Federal Emergency Management Agency (FEMA). During this time Jeff produced new floodplain maps for hundreds of miles of streams in Washington, Oregon, and Idaho. He conducted emergency post-flood assessments in Alaska, and provided input to FEMA’s on-going national Map Modernization Plan. Over the past eight years Larry has consulted on numerous occasions to King County’s Department of Natural Resources managing the technical teams developing new flood hazard maps for nearly every river in the County. Larry also directed the development of new Coastal Flood Hazard maps for more than 100 miles of Puget Sound shoreline. WSE routinely consults with local agencies and private clients to help them understand and satisfy floodplain development regulations and requirements. This has included several recent projects assisting municipalities to obtain certification of existing flood protection levees. They have also assisted numerous clients in the preparation of CLOMR and LOMR requests.

Examples of our work in floodplain management


Tolt River Flood Hazard and Habitat Corridor Master Plan

King County's River and Floodplain Management Section retained WSE and Herrera Environmental Consultants to develop a Corridor Management Plan for the lower six miles of the Tolt River near Carnation, WA.

Kittitas County FEMA Mapping

The Kittitas County Department of Public Works desired to better understand flood risk along ten streams that descend from Colockum and Ryegrass ridges north and east of the City of Ellensburg.

Lower Cedar River HEC-RAS 1D/2D Modeling

As part of the Cedar River Corridor Plan, the lower 2.6 miles of the Cedar River were modeled for both the current condition (with significant sediment aggradation) and a proposed dredged condition.

Snohomish County Master Drainage Plan Analysis

WSE was tasked under an On-call contract with Snohomish County to assist the County with Master Drainage Planning in the Lake Serene (Norma Creek) and Waxen Road (North Creek) drainage basins.

Yakima River Flood Hazard Reduction & Habitat Restoration Corridor Plan

Kittitas County Public Works and partners seek to develop an integrated vision / plan to reduce flood hazards and improve habitat along a three mile reach of the Yakima River near Ellensburg, Washington.

Teanaway River FEMA "No-Rise" Evaluation

Kittitas County Public Works asked WSE to develop a solution to a floodway development issue on the Middle Fork of the Teanaway River.

Penstock Breach Flood Routing

A client required an Emergency Action Plan (EAP) for the FERC licensing of a hydroelectric project in Utah.

White River Countyline Levee Setback Conditional Letter of Map Revision

WSE was retained by King County to develop an updated branched flow one-dimensional (1D) HEC-RAS hydraulic model of the White River from East Valley Highway (A St SE) in Auburn to the Stewart Road bridge (8th St E) in Sumner.

Middle Fork Snoqualmie River - Hydraulic Modeling and Analysis

King County intends to prepare a Corridor Management Plan for the Middle Fork Snoqualmie River from approximately Snoqualmie River Mile (RM) 45 near the Three Forks Natural Area (upstream of its confluence with the South Fork Snoqualmie River) to RM 49 near the community of Tanner.

Manastash Creek Post Flood Investigation & Flood Relief Alternatives

In May, 2011 a major flood on Manastash Creek near Ellensburg, WA caused significant damage to private property and public infrastructure.

Honolulu Light Rail Stream Crossings - Pearl Highlands Station

As part of a planned 20-mile elevated light rail project on the island of Oahu, WSE has partnered with Northwest Hydraulic Consultants to conduct hydraulic engineering for approximately 20 stream crossings.

Eastbank Esplanade Fire Dock "No Rise" Evaluation

The City of Portland Fire Bureau is seeking permits to update the existing Fire Dock and landward Fire Station along the east bank of the Willamette River in downtown Portland, OR.

Willamette River Waterfront Brownfield Cleanup Project - "No Rise" Evaluation

A 4000-foot long section of bank and bed within the Willamette River in downtown Portland, Oregon has been identified as a contaminated remediation site.

North Creek Levee Reach Hydraulic Monitoring

A 1 mile reach of North Creek in Bothell, Washington is confined between earthen flood control levees.

Chehalis River Basin Flood Hazard Mitigation Alternatives Analysis

WSE was selected as part of the Anchor QEA study team to evaluate a broad range of options for flood hazard reduction in the Chehalis River basin.